Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

903
FXUS63 KLOT 071111
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
611 AM CDT Tue Jul 7 2026

.KEY MESSAGES...

- Dry and more seasonable conditions expected through Wednesday
  before shower and thunderstorm chances return Thursday.

- A corridor of heavy rainfall may occur somewhere in the region
  Thursday-Friday, though confidence in whether impacts occur
  locally remains low.

&&

.DISCUSSION...
Issued at 316 AM CDT Tue Jul 7 2026

A break in the more active weather pattern is in store the next
few days with surface high pressure having settled across the
region. This should keep shower and thunderstorm chances to our
northwest through Wednesday. Temperatures today will be similar
to yesterday, perhaps a degree or two warmer, with highs in the
low to mid 80s. Light onshore winds paired with a reinforcing
lake breeze will keep temperatures cooler (70s) near the
lakeshore. The surface high will begin to shift southeast into
Wednesday which will bring a return to southwesterly low-level
flow and accordingly warmer temperatures (mid-upper 80s)
areawide, including near the lakeshore.

Meanwhile the upper level ridge begins to flatten out late
Wednesday into Thursday as a pair of low-amplitude waves move
across the Upper Midwest. Associated convection across Wisconsin
Wednesday evening may attempt to drift toward the state line,
though it should be in a decaying state and likely lead to not
much more than a few showers into far northern Illinois.

While confidence is high in a period of unsettled weather
returning during the Thursday-Friday timeframe, confidence in
the details remains low. This is owing to notable model spread
in the strength of a separate convectively augmented wave from
the Central Plains and whether or not it phases with the
aforementioned Upper Midwest wave(s). This will have notable
implications as to the degree of impacts that could occur here
locally, including the potential for flooding. PWATs will be
toward the upper end of climatology and supportive of torrential
rainfall rates. A stronger, slow moving disturbance would lead
to greater flooding concerns (0Z NAM) and localized severe
threat. Whereas a weaker system that is slower to phase with the
northern wave(s) would lead to lower rainfall totals and shift
the corridor southward (0Z ECMWF). This is an overall lower
predictability event given it will be dependent upon how
convection unfolds over the next couple of days to our west.
Given this uncertainty, the main message is to keep an eye on
the forecast.

While a few diurnally driven showers and storms can`t be ruled
out on Saturday, surface high pressure begins to expand back
across the region over the weekend into early next week which
should lead to mainly dry conditions into the first part of next
week with temperatures in the upper 80s to around 90.

Petr

&&

.AVIATION /12Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 611 AM CDT Tue Jul 7 2026

No major forecast concerns are expected for this TAF period as
high pressure will remain overhead. Winds this morning will be
light with speeds around 5 kts and directions generally out of
the north-northwest. Though, some wobbling of directions between
350-010 are possible at times this morning at ORD and MDW. By
midday (17-18z) a lake breeze will move inland and result in a
more definite easterly wind shift at ORD, MDW and GYY; but
speeds will remain light around 6-8 kts. Winds will once again
become light and variable after sunset before settling into a
southwest direction late tonight into Wednesday morning. Speeds
are expected to increase Wednesday into the 10-12 kt range with
some occasional teen kt gusts possible. Otherwise, expect mostly
clear VFR skies to prevail through the TAF period.

Yack

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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